Sirius Minerals : Debt Non Occurrence Event Notice

THIS NOTICE IS IMPORTANT AND REQUIRES THE IMMEDIATE ATTENTION OF BONDHOLDERS. IF ANY BONDHOLDER IS IN ANY DOUBT AS TO THE ACTION IT SHOULD TAKE, IT IS RECOMMENDED TO SEEK ITS OWN FINANCIAL AND/OR LEGAL ADVICE, INCLUDING IN RESPECT OF ANY TAX CONSEQUENCES, IMMEDIATELY FROM ITS BROKER, BANK MANAGER, SOLICITOR, ACCOUNTANT OR OTHER INDEPENDENT FINANCIAL, TAX OR LEGAL ADVISER.

Sirius Minerals Finance No.2 Limited

(the Issuer)

NOTICE TO HOLDERS

of the Issuer's outstanding

U.S.$400,000,000 5 per cent. Guaranteed Convertible Bonds due 2027
(the Bonds)

Guaranteed by, and convertible into Ordinary Shares of,

Sirius Minerals Plc (the Guarantor)

ISIN: XS1991116127 / Common Code: 199111612

Capitalised terms that are not defined in this notice shall have the meanings given to them in the Terms and Conditions of the Bonds (the Conditions).

17 September 2019

NOTICE IS HEREBY GIVENthat further to the Guarantor's announcement (the RNS Announcement) on the website of the London Stock Exchange plc dated 17 September 2019, a Stage 2 Debt Non-Occurrence Event occurred as at 17 September 2019. To view the RNS Announcement which shall be incorporated in, and form part of this notice, please paste the following URL into the address bar of your browser.

https://www.londonstockexchange.com/exchange/news/market-news/market-news-detail/SXX/14228907.html

Accordingly, the Bonds shall be automatically redeemed pursuant to Condition 7(f) on 7 October 2019 (being the Stage 2 Debt Non-Occurrence Event Redemption Date) at their Accreted Principal Amount (being U.S.$203,737.16 per U.S.$200,000 in principal amount of the Bonds) as at such date together with accrued and unpaid interest (being U.S.$1,222.22 per U.S.$200,000 in principal amount of the Bonds) up to (but excluding) such date.

Each Bondholder has the right to elect that its Bonds shall not be redeemed pursuant to the occurrence of such Stage 2 Debt Non-Occurrence Event. To exercise such right, the holder of the relevant Bonds must submit a duly completed notice of election (a Bondholder's Stage 2 Debt Non-Occurrence Event Notice) to the Principal Paying, Transfer and Conversion Agent that is received on or before 26 September 2019.

The form of Bondholder's Stage 2 Debt Non-Occurrence Event Notice is available upon request from the Principal Paying, Transfer and Conversion Agent, the contact details for which are set out below.

As required by Condition 6(p), the Guarantor also confirms that:

(i) the Exchange Price immediately prior to the occurrence of the Stage 2 Debt Non-Occurrence Event was U.S.$0.2443 per Ordinary Share; and

(ii) the Closing Price of the Ordinary Shares as on 16 September 2019 (being the latest practicable date prior to the occurrence of the Stage 2 Debt Non-Occurrence Event) was £0.10 per Ordinary Share.

Bondholders should read carefully the contents of this Notice, including the RNS Announcement incorporated by reference herein, for all information material to Bondholders concerning the Stage 2 Debt Non-Occurrence Event.

Questions and requests for assistance in connection with the delivery of Bondholder's Stage 2 Debt Non-Occurrence Event Notices should be directed to the Principal Paying, Transfer and Conversion Agent:

The Bank of New York Mellon, London Branch

One Canada Square

Canary Wharf

London E14 5AL

United Kingdom

Email: [e-mail]

Attention: Corporate Trust Administration

For further information in relation to the contents of this notice, Bondholders should contact the following:

Sirius Minerals Plc

Thomas Staley

Chief Financial Officer of Sirius Minerals Plc and Director of Sirius Minerals Finance No.2 Limited

Third Floor, Greener House

68 Haymarket

London SW1Y 4RF

United Kingdom

Telephone: [phone]

Email: [e-mail]